Carrier spring for magazine type firearms



May 9, 195 D. M. WHLLEAMS CARRIER SPRING FOR MAGAZINE TYPE FIREARMS 5 Sheets-Sheet 1 Filed March 10, 1947 mm om lnuenror' Warm Attorneys May 9, 1956 s Sheets-Sheet 2 Filed March 10, 1947 Afvorneqs FLLt: \A..w.........l....-:mm4=m a km NM v 8 N 6. EN

Aw mm hm May 9, 1950 D. M. WILLIAMS CARRIER SPRING FOR MAGAZINE TYPE FIREARMS Filed March 10, 1947 3 Sheets-Sheet 3 nuen ijor s mzd torneys to; oiier Patented May 9, 1950 CARRIER SPRING FOR MAGAZINE-TYPE. FIREARMS D d ms. N av n, 0.Q. ins.s. sn0r to 01in Industries, Inc., New Haven, Come}, a corporation of Delaware Application March 10, 1941.- Serial N0.. i-s3.6.1.7..

6 Claims. 1

Elle. present. invention. relates in general, to firearms, and. more. especially to improvements in,,selif-,-loading firearms-of the type having a tu-. bnlar. magazine. and cartridge-transfer means adapted. to, automatically transfer av cartridge from thetuhulargmagazine, to the chamber of the barrel each time. the firearm is. discharged.

Heretofore, the cartridge-transfer means of seI ;=1ioac1in firearmsof this class has consisted, n, generaLQ 011 a. pivoted cartridge-carrier, the iorwardend oi wbicnis. adapted normally to be res iently. held in a. depressed. position in the receiver, substantially, onnosite the. open rear end fgthelfiu u ax ma azine. by means of ancarrierpr g.arransei eensase-beneath a. rearwa1td1-7- elitfilldi l armof the carrier. The carrier is adapted to be elevated by the breechblockwhich, cli ring its forwardexoursion in the receiver, rides mtqerir t d dosum unt d on. the. rear arm. o thecarrier so astodepress the latter againstthe resistance, of therarrier-springand elevate the forwardendiofj the carrier; Dnringthe rearward xcursion ftheb e chb ck. he a e is adapted. o. pivo h .v 19s. ut-10f ath n y Suitable manner so. as to avoid elevating the carrier, suitable resilient-means being provided'to return the dog into the pathpf thebreechblock before it begins its forward excursion. Thus, the breech-.- block must; have. suiiicient kinetic ener during itsrearward excursiorr to overcome the resistance R of the dog -springa-nd sufiicient residual energy as itjstarts' forward'from its rearmost position in the receiver to overcome the resistance of the carrier-spring. Heretoforathe energy required toovercome the resistance offeredby these springs has beenprovided' bothpby utilizing a, relativelyheavybreechblocl; and" a relatively-ponderous action-return spring.

Anobieet of thepresent invention is to provide zen-improved self loading firearm.

A further-object of'the invention isto provide aself loading firearm with improved cartridgetransfer-means characterized by its simplicity of construction, relatively few working parts and superior action.

A still=1-urtherobject of the invention is to provide: a. self loading firearm With a Single spring which functionsboth as a. carrier-spring and as arspring for the carrier-actuatingdog.

A StiHifU-Pthfifi object of the invention is to, proride a. self-loadingfirea-rm with a single spring which: is adapted; toserve both as thespri-ngof he car ierr otuati g; dos s e. e h es. miss n e pr ng being o ar a e as bl eh uena ih srearwar nd qrrtar e purr latively little; resistance; to the-breechr 2. s ons, and, yetto erta e atiye yr ng. fierce oafiheea 1 a o.depr. h a t he reeqhb o ls mor di o its. mrward q tion the receiver,

ith, hea ere mother bj s, ew e will appear to thos skilled in, the artfro nthe re ent. iseleeui'e his. n n on n ud s... all a r n. e. i d sclosure him ts. a e v r. he. r o r re .whiqhare 9 leimss s a separate application.

th e em'e nr ns. d aw n s in, wh ch essin. m d s of r i 1 the n sent nv n len are shown forillnstrative purposes:

Fig. 1 is a broken side elevation partly in sec: tion of a Belt-loading firearm embodying: the improved cartridge-transfer means of this invert: tion;

Fig. 2 is an enlarged broken side el'evationin section of the receiver of the firearm including a portion ofthe buttstock, the barrel and the tubii; lar magazine, the parts of the fire-control mechanism and cartridge-transfer means being in the positions they assume when the breechbloclgis inits forward; breech-closing position and the hammer has been released;

Fig. 3 1s an enlarged broken side elevation in section similar toFig. 2; but showingthebreechblock adjacent the end of its rearward excursion inthe-receiver and a cartridge delivered onto the cartridge-carrier from the magazine;

Fig. 4' is an enlarged broken side elevation in section similar to Figs. 1 and 2, but with: the breechblock part way forward in the receiver; in which position the breechblock has engaged and depressed the carrier-actuating dog of the carrier so as: to elevate the forward end of the latter;

Fig. 5'isasectional elevation of the firearm on line 5"-5 ofFig. 2;

Fig. 6. is an enlarged fragmentary sectional end elevation. of" the trigger-plate on. line 6-6 of Fig. 2;, showing details of the actuating-dogtin combination, withthecarrier-spring;

Fig. 7- is adetached-plan view.- of" the trigger plate showing the carrier-- and carrier-actuating dog;

Fig; o; is; an enlarged perspective view of the c rrier;

Big. this. an: enlarged: perspective view of,- the carriei actuating-dog ofi'the-carrier;

Fig. 1 0.- is an; enlarged side elevation of, the breechblgockg and Fig: 1:1; an enlarged. perspective view of the springsoil'the carr r audits actuating dog,

presea wheat. Bee le -s reos; we breathe i'l1;8l lichosen for illustratingmhe. tion, is, of theself-loading, typemove rearwardl as a unit on discharge of the firearm, the barrel-extension being adapted to move forwardly relative to the breechblock and the latter subsequently moving forwardly auto matically to insert a fresh cartridge in the chamber of the barrel.

The self-loading firearm embodying the present invention includes a receiver l5, a triggerplate 1 B mounted in the underside of the receiver adjacent the rear end thereof, a barrel indicated by the reference character l1 and secured at its rear end by a threaded connection or the like in an aperture 58 in the front wall I9 of the receiver, a tubular magazine indicated by the reference character 20 and secured at its rear end in an aperture 2! in the front wall !9 of the receiver, and a buttstock indicated generally at 22 suitably secured to the rear wall 23 of the receiver.

Referring to Figs. 1 through 5, the receiver 15 has a top wall 24 and side walls 25 and 26 depending therefrom to form a substantially-inverted U-shaped chamber for accommodating the breechblock and the fire-control mechanism. The former is indicated generally at 21 and as shown in Fig. 5, is adapted to be supported in the receiver for both longitudinal and pivotal movement therein and to this end, suitable longitudinal guide-grooves 2t and 29 are provided in the inner walls of corresponding sides 25 and 25 of the receiver. The guide-groove 28 is adapted to slidingly support a bar 3!! which may combine the function of an action-bar and breechblock-supporting member, whereas the guide-groove 29 is adapted to slidingly support a finger-piece 3| adapted to support the opposite side of the breechblock and to permit manual operation of the breechblock, both the action-bar 3!] and finger-piece 3!, hereinafter referred to as guidemembers, having transverse apertures 32 and 33 respectively at their rear ends arranged to be aligned axia ly so as to receive a transverse pivot-pin 3d. The latter is adapted to be supported adjacent its opposite ends in substantially rocker-shaped cam-slots 35 formed in the transversely-spaced parallel depending side walls 36 of the breechblock, the action-bar 30 and fingerpiece 3| being connected to the outside faces of the corresponding side walls 36 of the breechblock by the respective outer ends of the transverse pivot-pin 34, as shown clearly in Fig. 5. In accordance with the construction, the breechblock is adapted to be supported between the guide-members 3i] and M for both longitudinal and pivotal movement in the receiver. Other details of the breechblock are considered immaterial to a clear and full disclosure of the present invention, it being suilicient to state that the breechblock is of relatively-light weight, is provided with an axially-mounted spring-loaded firing-pin 31, a spring-loaded ejector (not shown), and a locking-lug 3B, the latter being formed integrallv on the upper edge of the breechblock and adapted to interlock with a shoulder 39 of a longitudinal aperture 40 formed in the top wall of the barrel-extension 41 when the breechblock is in its forward elevated position in the receiver, so as to lock the breechblock in chamber-closing position. To this end, the aforesaid transverse pivot-pin 34 is adapted to pivotally connect the forward end of an operating-link 42 to the breechblock, the forward end of the link 42 engaging between the spaced parallel side walls 35 of the breechblock, as shown clearly in Fig. 5. The operating-link 42 extends rearwardly from the breechblock and is pivoted at its rear end to V the forward end of an inertia-bar 43 which is supported for longitudinal sliding movement in a sleeve 44 formed integrally or otherwise secured to the rear wall 23 of the receiver. As shown in Fig. 1, the sleeve 44 is arranged to extend rearwardly through a longitudinal aperture 45 in the forward end of the buttstock 22, the rear end of the sleeve being threadedly secured to the forward end of an action-spring guide-tube 450 which extends rearwardly through an axiallyaligned counterbore 4% of the aperture 45. The rear extremity of the guide-tube 455 may be closed by a suitable end-closure 49. The actionspring is indicated at 47 and is relatively light, its forward end being adapted to engage against a shoulder 48 at the rear extremity of the inertiabar, while its opposite end seats against the endclosure 45 of the guide-tube.

Briefly, when the firearm is discharged, the force of its recoil will momentarily displace the breechblock barrel-extension, and operating-link and inertia-bar assembly rearwardly as a unit in the receiver. Subsequently, however, the barrelextension will be positively stopped from further rearward movement, whereupon the residual energy of the operating-link and inertia-bar assembly will carry the operating-link rearwardly relative to the breechblock, so as to move the transverse pin 34 of the link rearwardly in the rocker-shaped cam-slots 35 of the breechblock and pivot its locking-lug 38 downwardly out of locked engagement with the shoulder 39 of the barrel-extension, whereupon the breechblock will be moved to its rearmost position in the receiver by its own residual energy and the gas pressure in the chamber of the barrel. Following the ejection of the fired shell and the introduction of a fresh cartridge into the receiver, the action-return spring 41 will move the operatinglink and breechblock forwardly into breech-closing position, in which position the locking-lug of the breechblock is again elevated into engagement with the shoulder 39 of the barrel-extension by the camming action of the transverse pin 34 in the rocker-shaped cam-slots of the breechblock.

The trigger-plate I6 is secured to the receiver l5 in any suitable manner and constitutes. in general, laterally-spaced parallel side walls 50 and 5! between which the hammer 52 is pivotally secured at at 53. The side walls 50 and 5| of the trigger-plate are adapted to make a tight friction fit between the respective lower edges of the rear portion of the side walls 25 and 25 of the receiver. The trigger-plate also embodies a trigger-guard 54 which encloses the finger-piece 55 of a trigger which is pivotally mounted in the trigger-plate, as at 55, and forms the usual part of the fire-control mechanism of the firearm for locking and releasing the hammer 52. The forward end of the trigger-plate l5 terminates substantially midway of the longitudinal length of the receiver 15 to provide a loading-opening 5'! forwardly thereof. Opening rearwardly into the loading-opening 5'! is the rear end of the tubular magazine 2!) which extends forwardly from the 5 forward wall 19 of the receiver l5 through a longitudinal clearance-groove formed in a forestock 58 which, in turn, extends forwardly beneath the barrel. The tubular magazine 20 houses the usual cartridge-follower 59 which is constantly urged rearwardly in the magazine by the customary helical magazine-spring 60.

Pivotally supported in the forward end of the trigger-plate on a transverse pin 6i and located barrel by the forward return movement of the breech-bolt, as will hereinafter appear. The carrier of the present embodiment has one arm 64 which, as shown in Figs. 7 and 8, is provided with a. reach 55 which extends rearwardly of the pivotpin 6! of the carrier, the reach 55 and that portion of the carrier in which the pivot-pin 6! is mounted being accommodated in a shallow longitudinal recess 66 formed vertically in the side wall 5! of the trigger-plate and intersecting the upper edge thereof.

For the purpose of swinging the cartridgecarrier, and in particular its forward end or spoon 63, in a counterclockwise direction about its pivot 6|, as seen in Fig. 2, so as to elevate a cartridge thereon into position for engagement by the forward face of the advancing breech-block, the reach 65 of the cartridge-carrier is provided with a carrier-actuating dog 68 which is mounted izra substantially-vertical slot 87 intersecting the rear end of the reach, the lower end of the carrieractuating dog, herein-after termed the dog or "actuating-dog 68, being pivoted in the slot 6? of the reach by a pin 59, as shown in Fig. 2. The actuating-dog is adapted to project upwardly normally, as hereinafter described, above the upper edge of the reach 65 and is provided at its upper extremity with a substantially-gableshaped surface comprising a forwardly-anddownwardly-inclined cam-surface l0 and a rearwardly-and-downwardly-inclined cam-surface I l. A suitable clearance-recess 72 is provided on the inside wall of the actuating-dog adjacent the back edge thereof, the upper end of which intersects the cam-surface H, as shown in Fig. 9. The forward edge of the clearance-recess forms a substantially-square shoulder '13 on the inside wall of the actuating-dog, as indicated in Figs. '7 and 9. The cam-surfaces IE! and Il on the upper end of the actuating-dog are adapted to project upwardly into the path of movement of the breechblock, for the purposes hereinafter described. Moreover, the upper end of the forward edge M of the dog presents a substantiallysquare shoulder which is adapted to be engaged by the leading edge 55 of a V-shaped notch it formed in the rear edge of the right-hand side wall 36 of the breechblock as the latter moves rearwardly in the receiver. Referring to Fig. 1.0, the lower edge of the right-hand side 36 of the breechblock comprises a substantially-fiat step 11 which is relatively-short and lies in the horizontal plane of the lower edge 78 of the left-hand side 36 of the breechblock, as indicated in Fig. 5. When the breechblook moves into its rearward position in the receiver, as indicated in Figs. 3 and 4, both the lower edge 18 of the left-hand side of the breechblock and the step l? of the righthand side are adapted to be supported on suitable longitudinal tracks '55 formed in the trigger-plate on corresponding sides thereof.

-' ofan upwardly-and-rearwardly-extending subd stantially-fiat cam-surface 8 2, the upper rear end of which intersects the lower end of the leading edge 15 of the V-shaped notch E6 in the back edge of the breechblock.

When the breechblock is in its forward breech closing position, both the cartridge-carrier and its actuating-dog are adapted to be held in their respective normal positions in the receiver, that is to say, the forward end or spoon 63 of the carrier is in its depressed position substantially opposite the exit end of the tubular magazine, while the carrier-actuating dog is held in an upright substantially-vertical position with respect to the carrier, as indicated in Fig. 2. To this end, resilient-means is provided comprising a single spring 83 which combines the functions of an actuating-dog spring and a carrier-spring. The spring 83 is a torsion-spring which, as shown in Fig. 11, comprises an upper arm 84 and a lower arm 85, both of which extend forwardly of the coil 86 of the spring. The torsion-spring 83 is adapted to move longitudinally freely in the receiver and to this end suitable mounting-means is provided comprising a longitudinal relief-recess E6 in the side 55 of the trigger-plate, the lower arm 55 and the lower edge of the coil 88 of the spring 8-3 engaging in a substantially-longitudinal relatively-narrow guide-groove 8'5 formed in the bottom of the relief-recess 86, as shown in Fig. 6. The rear wall 83 of the relief-recess 655 is formed with a rearWardly-extending aperture 89, see Fig. 7, substantially rectangular in cross section the inner wall of which is co-extensive with the inner face of the relief-recess t6, the outer wall 9% of the aperture 89 having a longitudinal rearwardly-extending slot hi, the forward end of which intersects the forward edge of the wall 83. The width and height of the aperture 89 are only slightly greater than the thickness and diameter respectively of the coil of the spring 83, whereby the latter is enabled to move freely rearwardly into the aperture 88 from its normal forward position in the relief-recess 55 as hereinafter described, the height of the longitudinal slot 9! in the outer wall 96 being less than the diameter of the coil 36 so as to provide a depending flange 82 to retain the coil in an upright position in its guide-groove 8?, see Fig. 6, during forward and rearward movement of the spring therein as hereinafter described.

The upper arm 84 of the torsion-spring 83 is adapted to engage in the clearance-space E2 on the inside face of the carrier-actuating dog and is adapted to be pivotally fastened as a 840 to the rear edge of the dog at a point thereon above its pivot 69. The force of the torsion-spring 83, acting through the upper arm 8 is adapted normally both to hold the carrier-actuating dog 68 in its normal upright forward position with respect to the reach 65 of the carrier and, through its connection therewith by the dog, to exert a force on the reach 65 to pivot the latter about its pivot 6! in a clockwise direction, as seen in Fig. 2, thereby to hold the forward end or spoon 63 of the carrier in its normal depressed cartridgereceivin position. This position of the torsionspring will be hereinafter referred to as its normal or "operating position, whereas, the retracted position of the spring shown in Figs.-3 and 4 will be referred to as its inoperative position. It will be observed that when the spring 83 is in its operating position, the vertical force vecttor of its upper arm 8t, acting at an on the actuating-dog 58, is afunction of the angle A which the upper arm 84 of the spring '3 and 4.

7 makes with respect to a line through its connection 840 with the dog and the pivot iii of the carrier, and is relatively large. Hence, the force moment acting about the pivot B! of the carrier to pivot the latter clockwise and hence hold its spoon in its normaldepressed position, will be relatively large. On the other hand, when the spring 83 is moved to its retracted position in the relief-recess, as shown in Figs. 3 and 4, the vertical force vector of the upper arm 34 of the spring will be reduced in proportion to the difference between the angle A and the angle B which the arm 8-4 now makes with the line through its connection 520 with the dog and the pivot 6! of the carrier. Hence, the force moment acting about the pivot 6! of the carrier to resist counterclockwise rotation thereof, will be proportionately smaller, that is to say, the

carrier-reach may be depressed to raise the spoon 63 with relatively little effort. Moreover, insofar as the pivotal movement of the actuating dog relative to the carrier is concerned, inasmuch as the spring 83 is free to move rearwardly in, its guide-slot, the upper arm 84- of the spring will offer relativel little resistance to the initial rearward pivotal movement of the dog about 7 its pivot 69.

'The operation of the device may be described briefly as follows. Assuming the breechblock is in its forward breech-closing position and that the trigger 55 has been pulled to release the hammer 52 which strikes the firing-pin 3'? to fire a cartridge in the chamber of the barrel, the force .of the gases created by the discharge of the cartridge will move thebreechblock 21 and barrel-extension 4! rearwardly in the receiver, in

substantially parallel to the longitudinal axis of the carrier-reach B5. The rearward pivotal movement of the actuating dog initially forces the upper arm 84 of the torsion-spring 83 rearwardly so as to move the spring to its rearmost position in the relief-recess 65 and thereafter depresses the spring-"arm 84, as indicated Figs. To the latter end, first the cam-surface 82 and then the step i? of the breechblock engage and ride over the forward edgev M of the actuating-dog, thereby holding the latter in its r rearwardly-depressed position as the breechbloek approaches its rearmost position in the receiver, At its rearmost position in the receiver, see Fig. 3, the step T! of the breechblock is carried beyond the cam-face iii of the carrier-actuating,

dog, whereupon the force of the depressed upper arm 84 of the torsion-spring pivots the actuating-dog upwardly into the relief-recess 8i, so that the cam-surface iii of the dog engages is in substantial engagement with. the shoulder 80 of the breechblock. During this interval, a fresh cartridge is adapted to be. released, from the. tubular magazine by a cartridge-stop or equivalent. device (not shown), onto the carrier,

and subsequently the breechblock, under the force of the compressed action-spring fill, begins to move forwardly in the receiver. The shoulder 80 of the breechblock thus exerts a force against the cam-surface iii of the: carrier-actuating dog,

,which force is, directed along a line above the dead-center line of the actuating-dog, .asa conq sequence of which the pivot 69 thereof is forced downwardly, as indicated in Fig. 4. This downward displacement of the pivot 69 at the rear extermity of the reach 65 of the carrier effects the concurrent upward pivotal movement .of the forward end 63 of the carrier, whereby the cartridge mounted thereon is elevated upwardly in the receiver to a position such that the forward end of the cartridge isopposite the chamber of the barrel, as indicated in Fig. 4. As the breech block continues its forward movement, its step 11 rides onto the cam-surface m of the dog, the frictional engagement of these two mutually-engaging surfaces suflicing to pivot the .dog 68 clockwise about its pivot 69. As the dog pivots forwardly, the torsion-spring 83 is carried for,- wardly bodily in the relief-recess 66, whereupon the force of its upper arm 84 acts to snap the dog forwardly into its normal forward position with respect to the carrier, in which position the downwardly-and-rearwardly-sloping camsurface 1! of the dog is moved into engagement with the step T! of the breechblock so as to hold the carrier-reach depressed as the breechblock continues its forward movement. During the transition of the cam-surface 10 from en,- gagement with the shoulder of the breech block to a position forwardly thereof, as indicated by the dotted lines in Fig. 4, the force of the torsion-spring 83, acting on the reach 65, may momentarily depress the carrier-spoon slightly. However, substantially immediate engagement of the step T! with the downwardly-and-rearwardly-sloping cam-surface H of the carrieractuating dog again elevates the forward end of the carrier, the elevation of which may be increased slightly as the step 11 of the breechblock advances into engagement with the forwardlyand-downwardly-sloping cam-surface 10 of the,

actuating-dog. Thereafter, as the step 11 of the breechblock leaves the cam-surface. Ill of the dog, the latter moves up into engagement with the upwardly-and-rearwardly-inclined cam-surface 82 of the breechblock, the slope of which permits the dog to be moved upwardly by the force of the spring-arm 84 acting thereon, to pivot the carrier in a clockwise direction so as to depress the forward end 553 thereof out of the path of the breechblock. The latter has already entered the fresh cartridge into the breech-end of the barrel and now advances the cartridge fully into the chamber. When the breechblock is locked in its foremost chamber-closing position in the receiver, the dog will be again in its normal operating position, as shown in Fig. 2, and the spoon 63 of the carrier will be opposite the rear opening of the tubular magazine in a position to receive the next cartridge therefrom. From the foregoing description and drawings, it will be clear that'in accordance with the present invention, a single spring is provided which acts both as a spring for the carrier-actuating dog-spring and as a carrier-spring to depress the forward end of the latter, the spring being so arranged that the relatively-strong force acting to hold the, carrier-spoon in its depressed position does not act through they dog to resist the rearward movement of the breechblock, the rearward bodily displacement of the spring; effectively reducing the resistance offered by the spring to the rearward pivotal movement of the dog and the subsequent elevation of the carrierspoon. It will be understood that the invention is equally applicable to a self loading firearm of .outgdeparting from the spirit and essentialchar- V acteristics of the invention, and the ,presentrembodiments are therefore, to be considered in all respects as illustrative and not restrictive, and all changes icoming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

1. In a self-loading firearm, the combination with;a=receiver; a barrel secured to said rgceiver and a tubular magazinesupported beneath said 'barrel; ofa b eech l ck r ci ooab m g edi 'saidre eiver; .a ca rie a ranged-to transfe rg i tridges from said magazine to the chamber of said barrel; carrier-supporting means secured to said receiver; a carrier-actuating dog mounted on said carrier, said carrier-actuating dog being arranged to be displaced relative to said carrier by said breechblock during the rearward excursion thereof; and resilient-means, said resilientmeans being mounted on said carrier-supporting means for longitudinal displacement relative thereto and engageable with said carrier-actuating dog so as to exert relatively-weak resistance to the displacement of said actuating-dog during the rearward excursion of said breechblock and to exert relatively-strong force on said carrier to hold it in its normal position when said breechblock is in its forward chamber-closing position.

2. In a self-loading firearm, the combination with a receiver; a barrel secured to said receiver and a tubular magazine supported beneath said barrel; of a breechblock reciprocably mounted in said receiver; a pivoted carrier arranged to transfer cartridges from said magazine to the chamber of said barrel; carrier-supporting means secured to said receiver; a carrier-actuating dog mounted on said carrier, said carrier-actuating dog being arranged to be displaced rearwardly with respect to said carrier by said breechblock during the rearward excursion thereof and to be moved forwardly from its rearward position by said breechblock during the forward movement thereof; and an actuating-dog spring connected to said dog, said spring being slidably mounted on said car-, rier-supporting means to exert relatively-weak resistance to the rearward displacement of said actuating-dog during the rearward excursion of said breechblock and to exert relatively-strong force on said carrier to hold the latter in its normal forward position when said breechblock is in its forward chamber-closing position.

3. In a self-loading firearm, the combination with a receiver having a trigger-plate secured thereto provided with a flanged groove; a barrel secured to said receiver and a tubular magazine supported beneath said barrel; of a breechblock reciprocably mounted in said receiver; a carrier pivotally mounted in said trigger-plate and arranged to transfer cartridges from said magazine to the chamber of said barrel; a carrieractuating dog movably mounted on said carrier, said carrier-actuating dog being arranged to be displaced rearwardly with respect to said carrier by said breechblock during the rearward excursion thereof and to be moved forwardly from its rearward position by said breechblock during the forward movement thereof; and an actuatingdog spring connected to said dog, said spring being supported in the flanged groove of said trigger-plate for longitudinal displacement and ;a tubular magazine .jsupporited beneath said barrel; of a breech-block reciprocably mounted in said receiver; a pivoted carrier arranged to wtherein so as to exert relatively-weak resistance to (the rearward-displacement of said actuating dog during the rearward excursion of said breechblock and to exert relatively-[strong force on said carrier to hold the latter in its normal forward position when said tbreechblooki's fin its ,forward chamber-closing position.

4. in self-loading firearm, t e ccmbination with a receiver; ,abarrel secured to said ltc'ei transfer cartridges from said magazine ,to the chamber of .said barrel; a carrier-actuatingdog ,pivotaliy mountedlonsaidcarriensaid carrier-ac terating rdog being arranged to be pivoted rear wardly with respect tosaid carrier by said breechblock during the rearward excursion thereof and to be pivoted forwardly from its rearward position by said breechblock during the forward movement thereof; an actuating-dog spring connected to said dog; and means to slidingly support said spring in said receiver for rearward displacement therein by the rearward pivotal movement of said dog, whereby said spring exerts relatively-weak resistance to the rearward pivotal movement of said actuating-dog during the rearward excursion of said breechblock, said spring being arranged to be moved forwardly by the forward pivotal movement of said actuating-dog to urge said actuating-dog into its normal forward position with respect to said carrier and to exert relativcly-strong force on said dog to hold said carrier in its normal position when said breechblock is in its forward chamber-closing position.

5. In a self-loading firearm, the combination with a receiver; a barrel secured to said receiver and a tubular magazine supported beneath said barrel; of a breechblock reciprocably mounted in said receiver; a pivoted carrier having a rearwardly-extending reach and a forwardly-extending arm arranged to transfer cartridges from said magazine to the chamber of said barrel; a carrier-actuating dog pivotally mounted on the rearwardly-extending reach of said carrier, said carrier-actuating dog being arranged to be engaged and pivoted rearwardly with respect to said carrier by said breechblock during the rearward excursion thereof and to be pivoted forwardly from its rearward position and simultaneously to be depressed by said breechblock during the forward movement thereof to pivot the rearwardly-extending reach of said carrier downwardly; an actuating-dog spring connected to said dog; and means to slidingly support said actuating-dog spring in said receiver for rearward displacement relative to said carrier by the rearward pivotal movement of said dog, whereby said spring exerts relatively-weak resistance to the rearward pivotal movement of said dog during the rearward excursion of said breechblock, said spring being arranged to be moved forwardly by the forward pivotal movement of said actuatingdog as said breechblock moves forwardly into chamber-closing position simultaneously to urge the actuating dog forwardly into its normal position with respect to said carrier and to pivot the rearwardly-extending reach of said carrierupwardly so as to depress the forwardly-extending arm of said carrier.

6. In a self-loading firearm, the combination with a receiver; a barrel secured to said receiver and a tubular magazine supported beneah said barrel; of a breechblock reciprocably mounted in "said receiver; a pivoted carrier. arranged to'transfer cartridges from said magazine to the chamber of said barrel; carrier-supporting means having a relief-recess in one wall thereof; a carrier actuating dog mounted on said carrier, said carrier-actuating dog having a normal position in said carrier and arranged to be displaced from its normal position relative to said carrier by said breechblock during the rearward excursion thereof so as to engage and hold said breechblock in its open position in said receiver; and a Single spring mounted to move longitudinally in the relief-recess of said carrier-supporting means so as to be displaced by the rearward displacement of said actuating-dog thereby to exert relativelyweak resistance to the rearward displacement thereof, said spring being arranged to be returned to its normal forward position in saidrei- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS "Number Name Date 1,852,411 Henry Apr. 5, 1932 2,090,340 Browning Aug. 1'7, 193'! 2,422,532 Dehm June 17, 194'! 

